Aqueous contrast agents for dynamic MRI and mra

Abstract

In a first aspect this invention provides methods comprising administering an aqueous contrast agent to the vascular system of a subject, and performing a magnetic resonance scan to detect the MR signal enhancement effects of the aqueous contrast agent. In embodiments the magnetic resonance scan comprises applying at least one pulse sequence selected from a PD-weighted pulse sequence, a T1-weighted pulse sequence, a T2-weighted pulse sequence, and a D-weighted pulse sequence. In embodiments the magnetic resonance scan comprises applying a T1-weighted pulse sequence. A system for performing perfusion MRI comprising an aqueous contrast solution and an injection apparatus configured to provide a maximum injection rate of the aqueous contrast solution to a subject vascular system of at least about 5 ml / s. is also provided.

Description

[0001]This application claims priority to U.S. Provisional Application No. 62 / 000,048, filed May 19, 2014, which is hereby incorporated herein.INTRODUCTION[0002]MRI contrast agents are a group of contrast media used to improve the visibility of soft tissues, organs and vasculature with magnetic resonance imaging (MRI). MRI offers a wide array of intrinsic tissue contrast mechanisms for aiding in the diagnosis of disease and these can be explored by simple manipulation of the imaging parameter values; a.k.a. pulse sequence parameters. Nonetheless, exogenous MRI contrast agents offer additional diagnostic information that is not easily obtainable with standard nonenhanced MRI techniques. In particular, gadolinium-based contrast agents (GBCA) are routinely used in the practice for diagnosing tissue pathology via contrast enhanced (CE) MRI, for assessing the vascular supply and the capillary bed integrity of biological tissue via magnetic resonance perfusion (MRP), and for providing hig...

AI Technical Summary

Benefits of technology

The patent text describes the use of a nontoxic sodium chloride water solution (NS) as a contrast agent for magnetic resonance imaging (MRI). NS injection can lead to a temporary increase in the relaxation times of blood and can enhance the visibility of soft tissues, organs, and vasculature with MRI. The use of NS as a contrast agent is novel and has not been previously reported. The technical effect of this patent is to provide a safer and effective contrast agent for MRI that can be used for dynamic perfusion MRI and to improve the accuracy and reliability of MRI diagnostics.

Problems solved by technology

Nonetheless, exogenous MRI contrast agents offer additional diagnostic information that is not easily obtainable with standard nonenhanced MRI techniques.

While GBCAs have many useful properties, GBCAs also have clinical limitations.

Data has also demonstrated that GBCAs may accumulate in several organ systems of the body and the possible detrimental effects of this are of concern.

Use of GBCAs also adds significantly to the total cost of MRI procedures.

This increases the economic burden of MRI and may discourage its use in some instances.

Furthermore, these investigators did not perform dynamic MRI scanning with the saline injection and instead two static MRI acquisitions were performed; one pre magnetized saline injection and a second scan one hour later.

However, the authors were concerned that in certain situations reduction in Hct concentration could confound MR results obtained from methods that depend on changes in the oxygen saturation.

This is likely because the authors appreciated that blood dilution alone is not sufficient to enhance T1-, T2-(to an extent), D-, and PD-weighted pulse sequences.

Gadolinium-based contrast agents can have risks including nephrogenic systemic fibrosis, allergic reactions and limitation of use during pregnancy.

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